JPH0220477Y2 - - Google Patents

Description

[Detailed Description of the Invention] <<Industrial Application Field>> This invention relates to a small rotary vane type gas compressor used in car coolers and the like.

[Prior art] Generally, in a small rotary gas compressor, lubricating oil is supplied to the vanes and rotor shaft from an oil reservoir provided in the casing using the discharge pressure of refrigerant gas to lubricate each part. , applying back pressure in the discharge direction of the vane. Furthermore, a part of the lubricating oil is supplied into a mechanical seal chamber formed between the drive shaft of the rotor and the bearing part of the casing, and the rotating side seal member provided in this part is pressed against the stationary side seal member. The inside of the mechanical seal chamber is sealed.

However, in such a gas compressor, the back pressure applied to the vanes is proportional to the discharge pressure. As a result, as the discharge pressure increases, the contact pressure of the vanes against the inner wall of the cylinder increases, and the sliding resistance increases.

At the same time, the pressure inside the mechanical seal chamber becomes high, and the sliding friction resistance of each seal member increases, increasing the drive resistance of the rotor and causing a decrease in efficiency.

For this reason, there are some devices in which the mechanical seal chamber and the gas supply side chamber are communicated through a communication hole.

With this structure, the vane back pressure and the pressure increase in the mechanical seal chamber due to the increase in discharge pressure are moderately suppressed, and the lubricating oil discharged from the mechanical seal chamber becomes oil mist and flows from the intake port to the cylinder chamber together with the intake gas. Due to its introduction inside, the sealing properties are increased, preventing recompression and thus reducing the discharge temperature.

However, when connecting holes are provided, lubricating oil flows into the intake boat side and sealing of sliding parts in the cylinder chamber etc. is improved, but the oil temperature is high and the viscosity is low, making it difficult to provide sufficient sealing performance. If the diameter of the communication hole is large, a large amount of lubricating oil will flow into the intake port side, and the proportion of oil in the gas sucked into the cylinder chamber will increase, causing cooling by the intake gas. This causes a decrease in efficiency, that is, a decrease in volumetric efficiency. For this,
There is a risk that the overall evaluation will result in poor performance.

<Purpose of the invention> This invention connects the mechanical seal chamber and the gas supply side chamber to appropriately suppress the vane back pressure and the pressure increase in the mechanical seal chamber, and lowers the average driving torque. It is an object of the present invention to provide a gas compressor with little reduction in volumetric efficiency and with sufficiently improved sealing performance on the cylinder chamber side.

<<Structure of the invention>> In order to achieve the above object, in the present invention, both chambers are connected by a heat exchanger made of a coiled pipe, one end of which communicates with the mechanical seal chamber and the other end of which communicates with the gas supply side chamber. It is characterized by

In other words, in this invention, by utilizing the fact that the flow rate loss of fluid is proportional to the pipe length, the flow rate of the lubricating oil flowing into the gas supply chamber is set to an appropriate amount, increasing the volumetric efficiency, and the lubricating oil is transmitted through the pipe line. By utilizing the fact that the viscosity of the lubricating oil increases as the lubricating oil is sufficiently cooled while traveling, the lubricating oil with high viscosity is intended to achieve a further sealing effect in the cylinder chamber, etc.

Embodiment FIG. 1 shows the overall structure of a small rotary vane type gas compressor according to a first embodiment of the present invention, and FIG. 2 is a half-sectional perspective view showing the main parts.

In the figure, the compressor includes a compressor main body 1 and a casing 2 with an open end that airtightly surrounds the main body 1.
and a front head 3 attached to the opening surface of the casing 2.

The main body 1 includes a cylinder 4 having an elliptical inner circumference, a front side block 6 and a rear side block 5 attached to both sides thereof, and is integrated into a cylinder chamber formed by these through rotor shafts 7 and 8. It consists of a fully cylindrical rotor. The rotor 9 has a plurality of slits radially formed in the same phase along its radial direction, and plate-shaped vanes 10 are held within these slits so as to be movable forward and backward.

A cylinder 4 is mounted on the rear end surface of the rear side block 5.
An oil separator 11 that communicates with gas discharge ports (none of which are shown) formed in each of the rear side blocks 5 and 5 is fixed.

The lubricating oil separated by the separator 11 flows into the gap 1 formed between the rear side block 5 and the casing 2.
The high pressure gas is stored in the gas discharge port 13 and circulated to each part again by the pressure of the high pressure gas discharged from the gas discharge port 13. That is, each side block 6, 5 and cylinder 4 are formed with oil passages 4b, 5a, 6c, respectively, which communicate with the outer periphery of each rotor shaft 7, 8.

The lubricating oil 14 is supplied to the V-shaped grooves 7b, 8a formed on the outer peripheries of the shafts 7, 8 through the respective oil passages 4b, 5a, 6c as shown by arrows A and B, and further into the V-shaped grooves 7b. , 8a and enters into each slit through ring grooves 9a formed on both end faces of the rotor 9, presses the tip of each vane 10 into the cylinder chamber, and connects each vane 10 with each side block 5, 6. Perform a seal.

Further, high-pressure oil passages 5b and 6d are formed through the side blocks 5 and 6, respectively, and the oil passage 6d on the front side block 6 side communicates with a mechanical seal chamber to be described later.

The front head 3 has its end face airtightly fixed to the outer peripheral end face of the casing 2 and the front side block 6 via a packing 15. An intake port 16 is formed in the upper part thereof, which communicates with gas supply ports 6a and 4a formed in the front side block 6 and the cylinder 4, respectively.

Furthermore, a cylindrical portion 18 is provided at the center of the front head 3 and is airtightly fitted to the outer periphery of a bearing portion 6b which is protruded from the center of the front side block 6 through a packing 17. The aforementioned mechanical seal chamber 19 is formed between the inner cylindrical portion of the shaped portion 18 and the protruding end 7a of the rotor shaft 7.

Inside the mechanical seal chamber 19, the tip abuts against a step 18a formed on the inner circumferential wall of the tip, and its outer circumference is fixed via a ring-shaped packing 20, and the tip of the rotor shaft 7 is rotatably mounted. Casting fixed side seal member 21 inserted through
and a movable side sealing member 22 having a substantially trapezoidal cross section and made of a carbon-formed body that comes into contact with this sealing member 21.
, a ring-shaped packing 22a disposed on the inner circumference of this seal member 22, and a fixed side seal member 2.
a spring 2 that is disposed at the rear end of 2 and always presses the seal member 22 against the rear end surface of the stationary seal member 21;
3, and a dish-shaped fixing member 24 that supports the rear end of this spring and is fixed to the outer periphery of the rotor shaft 7.

A locking protrusion 24a extends from the tip of the fixed member 24, and by engaging this protrusion 24a with a notch 22b formed on the outer periphery of the fixed seal member 22, the seal member 22 is fixed to the rotor shaft. Rotate in conjunction with the rotation in step 7.

One end 30a of a heat exchanger 30 passing through the inside and outside of the mechanical seal chamber 19 is fitted into the rear end of the cylindrical portion 18 of the front head 3 constructed as described above.

The heat exchanger 30 has a coil shape made of a material with high heat transfer efficiency such as a copper pipe, and the coil portion 31 is fixed by being wound two or three times around the outer circumference of the cylindrical portion 18. Further, the other end 30b side is opened into a gas supply side chamber formed between the front head 3 and the case 2.

Therefore, the lubricating oil supplied to the groove 7b of the rotor shaft 7 through the oil passages 4b and 6c is supplied to the rotor 9 side, and a portion of the lubricating oil is also supplied to the gap between the rotor shaft 7 and the bearing portion 6b and the oil passage. 6d into the mechanical seal chamber 19, and presses the movable seal member 22 against the fixed seal member 21 in cooperation with the biasing pressure of the spring 23. When this oil pressure increases beyond a predetermined level, the gas escapes through the heat exchanger 30 to the gas intake side.

In the process of passing through the inside of the coil portion 31, the lubricating oil comes into contact with the low-temperature suction gas introduced into the supply side chamber and undergoes heat exchange. Therefore, the temperature of the lubricating oil jetted into the supply side chamber from the end portion 30b decreases and becomes highly viscous.

This lubricating oil enters the cylinder chamber together with the gas through the suction ports 6a and 4a, is compressed as the rotor rotates, and is discharged from the discharge side.

At this time, since the lubricating oil has a particularly high viscosity, it increases the sealing effect, increases the compression ratio, and prevents the gas from being recompressed.

On the other hand, since the temperature of the suction gas increases, the degree of heating increases as the temperature rises, and the discharge temperature may also increase. Since the area is small, the effect of increasing the compression ratio due to the sealing effect is small. Since recompression is prevented, the discharge temperature is lowered, resulting in efficient compression work.

Naturally, the back pressure applied to the vane 10 is also reduced.

Although this example also has the above effects,
The decrease in volumetric efficiency is the same as in conventional compressors with communicating holes. However, the heat exchanger 30
By setting the diameter and length of the pipe to appropriate values, the pipe resistance and the amount of lubricating oil ejected accordingly are determined, so it is possible to easily determine the range in which the decrease in volumetric efficiency is small using these values.

Next, FIG. 3 shows another embodiment of this invention.
Note that the same parts in the figures as in the embodiment described above are designated by the same reference numerals, and the explanation thereof will be omitted.

In the figure, one end portion 40a of a heat exchanger 40 passing through the inside and outside of the mechanical seal chamber 19 is fitted into the cylindrical portion 18 of the front head 3, and a coil portion 41 following this is provided on the outside of the front head 3.
Further, the other end portion 40b passes through the end surface of the front head 3 and communicates with the gas supply side chamber.

In this embodiment, the lubricating oil leaving the mechanical seal chamber 19 exchanges heat with the outside air while passing through the coil portion 41, and in this state is ejected into the gas supply side chamber. Therefore, the degree of heating of the suction gas is reduced, and the temperature of the discharged gas can be further lowered.

<<Effects of the invention>> Since the present invention is constructed as described above, the flow rate of lubricating oil supplied into the gas supply side chamber can be controlled within the most efficient range, compared to the conventional one in which only a communication hole is provided. Can be set to . Further, since heat is exchanged during supply and the viscosity increases, the sealing effect can be further enhanced, recompression can be prevented, and the discharge temperature can be lowered.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing the overall configuration of a gas compressor according to a first embodiment of the present invention, Fig. 2 is a half-sectional perspective view showing the main parts, and Fig. 3 is a longitudinal cross-sectional view showing another embodiment. It is. 1...Compressor main body, 2...Casing, 3...
Front head, 4...Cylinder, 5...Rear side block, 6...Front side block,
7, 8... Rotor shaft, 9... Rotor, 10... Vane, 19... Mechanical seal chamber, 30, 40
...Heat exchanger, 30a, 40a...One end, 30
b, 40b...other end portion, 31, 41... coil portion.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a gas compressor configured to supply lubricating oil under discharge pressure to the bottom of the vane and into a mechanical seal chamber communicating with the bottom of the vane, one end is connected to the mechanical seal chamber. A gas compressor characterized in that both chambers are connected by a heat exchanger of a coiled pipe, the other end of which communicates with the chamber on the gas supply side. (2) The gas compressor according to claim 1, wherein the coil portion of the heat exchanger is disposed within the gas supply side chamber. (3) The gas compressor according to claim 1, wherein the coil portion of the heat exchanger is placed in contact with the outside air.